drivers/md/dm-raid.c

   1 /*
   2  * Copyright (C) 2010-2011 Neil Brown
   3  * Copyright (C) 2010-2011 Red Hat, Inc. All rights reserved.
   4  *
   5  * This file is released under the GPL.
   6  */
   7
   8 #include <linux/slab.h>
   9 #include <linux/module.h>
  10
  11 #include "md.h"
  12 #include "raid1.h"
  13 #include "raid5.h"
  14 #include "bitmap.h"
  15
  16 #include <linux/device-mapper.h>
  17
  18 #define DM_MSG_PREFIX "raid"
  19
  20 /*
  21  * The following flags are used by dm-raid.c to set up the array state.
  22  * They must be cleared before md_run is called.
  23  */
  24 #define FirstUse 10             /* rdev flag */
  25
  26 struct raid_dev {
  27         /*
  28          * Two DM devices, one to hold metadata and one to hold the
  29          * actual data/parity.  The reason for this is to not confuse
  30          * ti->len and give more flexibility in altering size and
  31          * characteristics.
  32          *
  33          * While it is possible for this device to be associated
  34          * with a different physical device than the data_dev, it
  35          * is intended for it to be the same.
  36          *    |--------- Physical Device ---------|
  37          *    |- meta_dev -|------ data_dev ------|
  38          */
  39         struct dm_dev *meta_dev;
  40         struct dm_dev *data_dev;
  41         struct md_rdev rdev;
  42 };
  43
  44 /*
  45  * Flags for rs->print_flags field.
  46  */
  47 #define DMPF_SYNC              0x1
  48 #define DMPF_NOSYNC            0x2
  49 #define DMPF_REBUILD           0x4
  50 #define DMPF_DAEMON_SLEEP      0x8
  51 #define DMPF_MIN_RECOVERY_RATE 0x10
  52 #define DMPF_MAX_RECOVERY_RATE 0x20
  53 #define DMPF_MAX_WRITE_BEHIND  0x40
  54 #define DMPF_STRIPE_CACHE      0x80
  55 #define DMPF_REGION_SIZE       0X100
  56 struct raid_set {
  57         struct dm_target *ti;
  58
  59         uint32_t bitmap_loaded;
  60         uint32_t print_flags;
  61
  62         struct mddev md;
  63         struct raid_type *raid_type;
  64         struct dm_target_callbacks callbacks;
  65
  66         struct raid_dev dev[0];
  67 };
  68
  69 /* Supported raid types and properties. */
  70 static struct raid_type {
  71         const char *name;               /* RAID algorithm. */
  72         const char *descr;              /* Descriptor text for logging. */
  73         const unsigned parity_devs;     /* # of parity devices. */
  74         const unsigned minimal_devs;    /* minimal # of devices in set. */
  75         const unsigned level;           /* RAID level. */
  76         const unsigned algorithm;       /* RAID algorithm. */
  77 } raid_types[] = {
  78         {"raid1",    "RAID1 (mirroring)",               0, 2, 1, 0 /* NONE */},
  79         {"raid4",    "RAID4 (dedicated parity disk)",   1, 2, 5, ALGORITHM_PARITY_0},
  80         {"raid5_la", "RAID5 (left asymmetric)",         1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
  81         {"raid5_ra", "RAID5 (right asymmetric)",        1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
  82         {"raid5_ls", "RAID5 (left symmetric)",          1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
  83         {"raid5_rs", "RAID5 (right symmetric)",         1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
  84         {"raid6_zr", "RAID6 (zero restart)",            2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
  85         {"raid6_nr", "RAID6 (N restart)",               2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
  86         {"raid6_nc", "RAID6 (N continue)",              2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
  87 };
  88
  89 static struct raid_type *get_raid_type(char *name)
  90 {
  91         int i;
  92
  93         for (i = 0; i < ARRAY_SIZE(raid_types); i++)
  94                 if (!strcmp(raid_types[i].name, name))
  95                         return &raid_types[i];
  96
  97         return NULL;
  98 }
  99
 100 static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
 101 {
 102         unsigned i;
 103         struct raid_set *rs;
 104         sector_t sectors_per_dev;
 105
 106         if (raid_devs <= raid_type->parity_devs) {
 107                 ti->error = "Insufficient number of devices";
 108                 return ERR_PTR(-EINVAL);
 109         }
 110
 111         sectors_per_dev = ti->len;
 112         if ((raid_type->level > 1) &&
 113             sector_div(sectors_per_dev, (raid_devs - raid_type->parity_devs))) {
 114                 ti->error = "Target length not divisible by number of data devices";
 115                 return ERR_PTR(-EINVAL);
 116         }
 117
 118         rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
 119         if (!rs) {
 120                 ti->error = "Cannot allocate raid context";
 121                 return ERR_PTR(-ENOMEM);
 122         }
 123
 124         mddev_init(&rs->md);
 125
 126         rs->ti = ti;
 127         rs->raid_type = raid_type;
 128         rs->md.raid_disks = raid_devs;
 129         rs->md.level = raid_type->level;
 130         rs->md.new_level = rs->md.level;
 131         rs->md.dev_sectors = sectors_per_dev;
 132         rs->md.layout = raid_type->algorithm;
 133         rs->md.new_layout = rs->md.layout;
 134         rs->md.delta_disks = 0;
 135         rs->md.recovery_cp = 0;
 136
 137         for (i = 0; i < raid_devs; i++)
 138                 md_rdev_init(&rs->dev[i].rdev);
 139
 140         /*
 141          * Remaining items to be initialized by further RAID params:
 142          *  rs->md.persistent
 143          *  rs->md.external
 144          *  rs->md.chunk_sectors
 145          *  rs->md.new_chunk_sectors
 146          */
 147
 148         return rs;
 149 }
 150
 151 static void context_free(struct raid_set *rs)
 152 {
 153         int i;
 154
 155         for (i = 0; i < rs->md.raid_disks; i++) {
 156                 if (rs->dev[i].meta_dev)
 157                         dm_put_device(rs->ti, rs->dev[i].meta_dev);
 158                 md_rdev_clear(&rs->dev[i].rdev);
 159                 if (rs->dev[i].data_dev)
 160                         dm_put_device(rs->ti, rs->dev[i].data_dev);
 161         }
 162
 163         kfree(rs);
 164 }
 165
 166 /*
 167  * For every device we have two words
 168  *  <meta_dev>: meta device name or '-' if missing
 169  *  <data_dev>: data device name or '-' if missing
 170  *
 171  * The following are permitted:
 172  *    - -
 173  *    - <data_dev>
 174  *    <meta_dev> <data_dev>
 175  *
 176  * The following is not allowed:
 177  *    <meta_dev> -
 178  *
 179  * This code parses those words.  If there is a failure,
 180  * the caller must use context_free to unwind the operations.
 181  */
 182 static int dev_parms(struct raid_set *rs, char **argv)
 183 {
 184         int i;
 185         int rebuild = 0;
 186         int metadata_available = 0;
 187         int ret = 0;
 188
 189         for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
 190                 rs->dev[i].rdev.raid_disk = i;
 191
 192                 rs->dev[i].meta_dev = NULL;
 193                 rs->dev[i].data_dev = NULL;
 194
 195                 /*
 196                  * There are no offsets, since there is a separate device
 197                  * for data and metadata.
 198                  */
 199                 rs->dev[i].rdev.data_offset = 0;
 200                 rs->dev[i].rdev.mddev = &rs->md;
 201
 202                 if (strcmp(argv[0], "-")) {
 203                         ret = dm_get_device(rs->ti, argv[0],
 204                                             dm_table_get_mode(rs->ti->table),
 205                                             &rs->dev[i].meta_dev);
 206                         rs->ti->error = "RAID metadata device lookup failure";
 207                         if (ret)
 208                                 return ret;
 209
 210                         rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
 211                         if (!rs->dev[i].rdev.sb_page)
 212                                 return -ENOMEM;
 213                 }
 214
 215                 if (!strcmp(argv[1], "-")) {
 216                         if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
 217                             (!rs->dev[i].rdev.recovery_offset)) {
 218                                 rs->ti->error = "Drive designated for rebuild not specified";
 219                                 return -EINVAL;
 220                         }
 221
 222                         rs->ti->error = "No data device supplied with metadata device";
 223                         if (rs->dev[i].meta_dev)
 224                                 return -EINVAL;
 225
 226                         continue;
 227                 }
 228
 229                 ret = dm_get_device(rs->ti, argv[1],
 230                                     dm_table_get_mode(rs->ti->table),
 231                                     &rs->dev[i].data_dev);
 232                 if (ret) {
 233                         rs->ti->error = "RAID device lookup failure";
 234                         return ret;
 235                 }
 236
 237                 if (rs->dev[i].meta_dev) {
 238                         metadata_available = 1;
 239                         rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
 240                 }
 241                 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
 242                 list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
 243                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 244                         rebuild++;
 245         }
 246
 247         if (metadata_available) {
 248                 rs->md.external = 0;
 249                 rs->md.persistent = 1;
 250                 rs->md.major_version = 2;
 251         } else if (rebuild && !rs->md.recovery_cp) {
 252                 /*
 253                  * Without metadata, we will not be able to tell if the array
 254                  * is in-sync or not - we must assume it is not.  Therefore,
 255                  * it is impossible to rebuild a drive.
 256                  *
 257                  * Even if there is metadata, the on-disk information may
 258                  * indicate that the array is not in-sync and it will then
 259                  * fail at that time.
 260                  *
 261                  * User could specify 'nosync' option if desperate.
 262                  */
 263                 DMERR("Unable to rebuild drive while array is not in-sync");
 264                 rs->ti->error = "RAID device lookup failure";
 265                 return -EINVAL;
 266         }
 267
 268         return 0;
 269 }
 270
 271 /*
 272  * validate_region_size
 273  * @rs
 274  * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
 275  *
 276  * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
 277  * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
 278  *
 279  * Returns: 0 on success, -EINVAL on failure.
 280  */
 281 static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 282 {
 283         unsigned long min_region_size = rs->ti->len / (1 << 21);
 284
 285         if (!region_size) {
 286                 /*
 287                  * Choose a reasonable default.  All figures in sectors.
 288                  */
 289                 if (min_region_size > (1 << 13)) {
 290                         DMINFO("Choosing default region size of %lu sectors",
 291                                region_size);
 292                         region_size = min_region_size;
 293                 } else {
 294                         DMINFO("Choosing default region size of 4MiB");
 295                         region_size = 1 << 13; /* sectors */
 296                 }
 297         } else {
 298                 /*
 299                  * Validate user-supplied value.
 300                  */
 301                 if (region_size > rs->ti->len) {
 302                         rs->ti->error = "Supplied region size is too large";
 303                         return -EINVAL;
 304                 }
 305
 306                 if (region_size < min_region_size) {
 307                         DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 308                               region_size, min_region_size);
 309                         rs->ti->error = "Supplied region size is too small";
 310                         return -EINVAL;
 311                 }
 312
 313                 if (!is_power_of_2(region_size)) {
 314                         rs->ti->error = "Region size is not a power of 2";
 315                         return -EINVAL;
 316                 }
 317
 318                 if (region_size < rs->md.chunk_sectors) {
 319                         rs->ti->error = "Region size is smaller than the chunk size";
 320                         return -EINVAL;
 321                 }
 322         }
 323
 324         /*
 325          * Convert sectors to bytes.
 326          */
 327         rs->md.bitmap_info.chunksize = (region_size << 9);
 328
 329         return 0;
 330 }
 331
 332 /*
 333  * Possible arguments are...
 334  *      <chunk_size> [optional_args]
 335  *
 336  * Argument definitions
 337  *    <chunk_size>                      The number of sectors per disk that
 338  *                                      will form the "stripe"
 339  *    [[no]sync]                        Force or prevent recovery of the
 340  *                                      entire array
 341  *    [rebuild <idx>]                   Rebuild the drive indicated by the index
 342  *    [daemon_sleep <ms>]               Time between bitmap daemon work to
 343  *                                      clear bits
 344  *    [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 345  *    [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 346  *    [write_mostly <idx>]              Indicate a write mostly drive via index
 347  *    [max_write_behind <sectors>]      See '-write-behind=' (man mdadm)
 348  *    [stripe_cache <sectors>]          Stripe cache size for higher RAIDs
 349  *    [region_size <sectors>]           Defines granularity of bitmap
 350  */
 351 static int parse_raid_params(struct raid_set *rs, char **argv,
 352                              unsigned num_raid_params)
 353 {
 354         unsigned i, rebuild_cnt = 0;
 355         unsigned long value, region_size = 0;
 356         sector_t max_io_len;
 357         char *key;
 358
 359         /*
 360          * First, parse the in-order required arguments
 361          * "chunk_size" is the only argument of this type.
 362          */
 363         if ((strict_strtoul(argv[0], 10, &value) < 0)) {
 364                 rs->ti->error = "Bad chunk size";
 365                 return -EINVAL;
 366         } else if (rs->raid_type->level == 1) {
 367                 if (value)
 368                         DMERR("Ignoring chunk size parameter for RAID 1");
 369                 value = 0;
 370         } else if (!is_power_of_2(value)) {
 371                 rs->ti->error = "Chunk size must be a power of 2";
 372                 return -EINVAL;
 373         } else if (value < 8) {
 374                 rs->ti->error = "Chunk size value is too small";
 375                 return -EINVAL;
 376         }
 377
 378         rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
 379         argv++;
 380         num_raid_params--;
 381
 382         /*
 383          * We set each individual device as In_sync with a completed
 384          * 'recovery_offset'.  If there has been a device failure or
 385          * replacement then one of the following cases applies:
 386          *
 387          *   1) User specifies 'rebuild'.
 388          *      - Device is reset when param is read.
 389          *   2) A new device is supplied.
 390          *      - No matching superblock found, resets device.
 391          *   3) Device failure was transient and returns on reload.
 392          *      - Failure noticed, resets device for bitmap replay.
 393          *   4) Device hadn't completed recovery after previous failure.
 394          *      - Superblock is read and overrides recovery_offset.
 395          *
 396          * What is found in the superblocks of the devices is always
 397          * authoritative, unless 'rebuild' or '[no]sync' was specified.
 398          */
 399         for (i = 0; i < rs->md.raid_disks; i++) {
 400                 set_bit(In_sync, &rs->dev[i].rdev.flags);
 401                 rs->dev[i].rdev.recovery_offset = MaxSector;
 402         }
 403
 404         /*
 405          * Second, parse the unordered optional arguments
 406          */
 407         for (i = 0; i < num_raid_params; i++) {
 408                 if (!strcasecmp(argv[i], "nosync")) {
 409                         rs->md.recovery_cp = MaxSector;
 410                         rs->print_flags |= DMPF_NOSYNC;
 411                         continue;
 412                 }
 413                 if (!strcasecmp(argv[i], "sync")) {
 414                         rs->md.recovery_cp = 0;
 415                         rs->print_flags |= DMPF_SYNC;
 416                         continue;
 417                 }
 418
 419                 /* The rest of the optional arguments come in key/value pairs */
 420                 if ((i + 1) >= num_raid_params) {
 421                         rs->ti->error = "Wrong number of raid parameters given";
 422                         return -EINVAL;
 423                 }
 424
 425                 key = argv[i++];
 426                 if (strict_strtoul(argv[i], 10, &value) < 0) {
 427                         rs->ti->error = "Bad numerical argument given in raid params";
 428                         return -EINVAL;
 429                 }
 430
 431                 if (!strcasecmp(key, "rebuild")) {
 432                         rebuild_cnt++;
 433                         if (((rs->raid_type->level != 1) &&
 434                              (rebuild_cnt > rs->raid_type->parity_devs)) ||
 435                             ((rs->raid_type->level == 1) &&
 436                              (rebuild_cnt > (rs->md.raid_disks - 1)))) {
 437                                 rs->ti->error = "Too many rebuild devices specified for given RAID type";
 438                                 return -EINVAL;
 439                         }
 440                         if (value > rs->md.raid_disks) {
 441                                 rs->ti->error = "Invalid rebuild index given";
 442                                 return -EINVAL;
 443                         }
 444                         clear_bit(In_sync, &rs->dev[value].rdev.flags);
 445                         rs->dev[value].rdev.recovery_offset = 0;
 446                         rs->print_flags |= DMPF_REBUILD;
 447                 } else if (!strcasecmp(key, "write_mostly")) {
 448                         if (rs->raid_type->level != 1) {
 449                                 rs->ti->error = "write_mostly option is only valid for RAID1";
 450                                 return -EINVAL;
 451                         }
 452                         if (value >= rs->md.raid_disks) {
 453                                 rs->ti->error = "Invalid write_mostly drive index given";
 454                                 return -EINVAL;
 455                         }
 456                         set_bit(WriteMostly, &rs->dev[value].rdev.flags);
 457                 } else if (!strcasecmp(key, "max_write_behind")) {
 458                         if (rs->raid_type->level != 1) {
 459                                 rs->ti->error = "max_write_behind option is only valid for RAID1";
 460                                 return -EINVAL;
 461                         }
 462                         rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
 463
 464                         /*
 465                          * In device-mapper, we specify things in sectors, but
 466                          * MD records this value in kB
 467                          */
 468                         value /= 2;
 469                         if (value > COUNTER_MAX) {
 470                                 rs->ti->error = "Max write-behind limit out of range";
 471                                 return -EINVAL;
 472                         }
 473                         rs->md.bitmap_info.max_write_behind = value;
 474                 } else if (!strcasecmp(key, "daemon_sleep")) {
 475                         rs->print_flags |= DMPF_DAEMON_SLEEP;
 476                         if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
 477                                 rs->ti->error = "daemon sleep period out of range";
 478                                 return -EINVAL;
 479                         }
 480                         rs->md.bitmap_info.daemon_sleep = value;
 481                 } else if (!strcasecmp(key, "stripe_cache")) {
 482                         rs->print_flags |= DMPF_STRIPE_CACHE;
 483
 484                         /*
 485                          * In device-mapper, we specify things in sectors, but
 486                          * MD records this value in kB
 487                          */
 488                         value /= 2;
 489
 490                         if (rs->raid_type->level < 5) {
 491                                 rs->ti->error = "Inappropriate argument: stripe_cache";
 492                                 return -EINVAL;
 493                         }
 494                         if (raid5_set_cache_size(&rs->md, (int)value)) {
 495                                 rs->ti->error = "Bad stripe_cache size";
 496                                 return -EINVAL;
 497                         }
 498                 } else if (!strcasecmp(key, "min_recovery_rate")) {
 499                         rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
 500                         if (value > INT_MAX) {
 501                                 rs->ti->error = "min_recovery_rate out of range";
 502                                 return -EINVAL;
 503                         }
 504                         rs->md.sync_speed_min = (int)value;
 505                 } else if (!strcasecmp(key, "max_recovery_rate")) {
 506                         rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
 507                         if (value > INT_MAX) {
 508                                 rs->ti->error = "max_recovery_rate out of range";
 509                                 return -EINVAL;
 510                         }
 511                         rs->md.sync_speed_max = (int)value;
 512                 } else if (!strcasecmp(key, "region_size")) {
 513                         rs->print_flags |= DMPF_REGION_SIZE;
 514                         region_size = value;
 515                 } else {
 516                         DMERR("Unable to parse RAID parameter: %s", key);
 517                         rs->ti->error = "Unable to parse RAID parameters";
 518                         return -EINVAL;
 519                 }
 520         }
 521
 522         if (validate_region_size(rs, region_size))
 523                 return -EINVAL;
 524
 525         if (rs->md.chunk_sectors)
 526                 max_io_len = rs->md.chunk_sectors;
 527         else
 528                 max_io_len = region_size;
 529
 530         if (dm_set_target_max_io_len(rs->ti, max_io_len))
 531                 return -EINVAL;
 532
 533         /* Assume there are no metadata devices until the drives are parsed */
 534         rs->md.persistent = 0;
 535         rs->md.external = 1;
 536
 537         return 0;
 538 }
 539
 540 static void do_table_event(struct work_struct *ws)
 541 {
 542         struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
 543
 544         dm_table_event(rs->ti->table);
 545 }
 546
 547 static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
 548 {
 549         struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
 550
 551         if (rs->raid_type->level == 1)
 552                 return md_raid1_congested(&rs->md, bits);
 553
 554         return md_raid5_congested(&rs->md, bits);
 555 }
 556
 557 /*
 558  * This structure is never routinely used by userspace, unlike md superblocks.
 559  * Devices with this superblock should only ever be accessed via device-mapper.
 560  */
 561 #define DM_RAID_MAGIC 0x64526D44
 562 struct dm_raid_superblock {
 563         __le32 magic;           /* "DmRd" */
 564         __le32 features;        /* Used to indicate possible future changes */
 565
 566         __le32 num_devices;     /* Number of devices in this array. (Max 64) */
 567         __le32 array_position;  /* The position of this drive in the array */
 568
 569         __le64 events;          /* Incremented by md when superblock updated */
 570         __le64 failed_devices;  /* Bit field of devices to indicate failures */
 571
 572         /*
 573          * This offset tracks the progress of the repair or replacement of
 574          * an individual drive.
 575          */
 576         __le64 disk_recovery_offset;
 577
 578         /*
 579          * This offset tracks the progress of the initial array
 580          * synchronisation/parity calculation.
 581          */
 582         __le64 array_resync_offset;
 583
 584         /*
 585          * RAID characteristics
 586          */
 587         __le32 level;
 588         __le32 layout;
 589         __le32 stripe_sectors;
 590
 591         __u8 pad[452];          /* Round struct to 512 bytes. */
 592                                 /* Always set to 0 when writing. */
 593 } __packed;
 594
 595 static int read_disk_sb(struct md_rdev *rdev, int size)
 596 {
 597         BUG_ON(!rdev->sb_page);
 598
 599         if (rdev->sb_loaded)
 600                 return 0;
 601
 602         if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
 603                 DMERR("Failed to read superblock of device at position %d",
 604                       rdev->raid_disk);
 605                 md_error(rdev->mddev, rdev);
 606                 return -EINVAL;
 607         }
 608
 609         rdev->sb_loaded = 1;
 610
 611         return 0;
 612 }
 613
 614 static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
 615 {
 616         int i;
 617         uint64_t failed_devices;
 618         struct dm_raid_superblock *sb;
 619         struct raid_set *rs = container_of(mddev, struct raid_set, md);
 620
 621         sb = page_address(rdev->sb_page);
 622         failed_devices = le64_to_cpu(sb->failed_devices);
 623
 624         for (i = 0; i < mddev->raid_disks; i++)
 625                 if (!rs->dev[i].data_dev ||
 626                     test_bit(Faulty, &(rs->dev[i].rdev.flags)))
 627                         failed_devices |= (1ULL << i);
 628
 629         memset(sb, 0, sizeof(*sb));
 630
 631         sb->magic = cpu_to_le32(DM_RAID_MAGIC);
 632         sb->features = cpu_to_le32(0);  /* No features yet */
 633
 634         sb->num_devices = cpu_to_le32(mddev->raid_disks);
 635         sb->array_position = cpu_to_le32(rdev->raid_disk);
 636
 637         sb->events = cpu_to_le64(mddev->events);
 638         sb->failed_devices = cpu_to_le64(failed_devices);
 639
 640         sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
 641         sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
 642
 643         sb->level = cpu_to_le32(mddev->level);
 644         sb->layout = cpu_to_le32(mddev->layout);
 645         sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
 646 }
 647
 648 /*
 649  * super_load
 650  *
 651  * This function creates a superblock if one is not found on the device
 652  * and will decide which superblock to use if there's a choice.
 653  *
 654  * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
 655  */
 656 static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
 657 {
 658         int ret;
 659         struct dm_raid_superblock *sb;
 660         struct dm_raid_superblock *refsb;
 661         uint64_t events_sb, events_refsb;
 662
 663         rdev->sb_start = 0;
 664         rdev->sb_size = sizeof(*sb);
 665
 666         ret = read_disk_sb(rdev, rdev->sb_size);
 667         if (ret)
 668                 return ret;
 669
 670         sb = page_address(rdev->sb_page);
 671
 672         /*
 673          * Two cases that we want to write new superblocks and rebuild:
 674          * 1) New device (no matching magic number)
 675          * 2) Device specified for rebuild (!In_sync w/ offset == 0)
 676          */
 677         if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
 678             (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
 679                 super_sync(rdev->mddev, rdev);
 680
 681                 set_bit(FirstUse, &rdev->flags);
 682
 683                 /* Force writing of superblocks to disk */
 684                 set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
 685
 686                 /* Any superblock is better than none, choose that if given */
 687                 return refdev ? 0 : 1;
 688         }
 689
 690         if (!refdev)
 691                 return 1;
 692
 693         events_sb = le64_to_cpu(sb->events);
 694
 695         refsb = page_address(refdev->sb_page);
 696         events_refsb = le64_to_cpu(refsb->events);
 697
 698         return (events_sb > events_refsb) ? 1 : 0;
 699 }
 700
 701 static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
 702 {
 703         int role;
 704         struct raid_set *rs = container_of(mddev, struct raid_set, md);
 705         uint64_t events_sb;
 706         uint64_t failed_devices;
 707         struct dm_raid_superblock *sb;
 708         uint32_t new_devs = 0;
 709         uint32_t rebuilds = 0;
 710         struct md_rdev *r;
 711         struct dm_raid_superblock *sb2;
 712
 713         sb = page_address(rdev->sb_page);
 714         events_sb = le64_to_cpu(sb->events);
 715         failed_devices = le64_to_cpu(sb->failed_devices);
 716
 717         /*
 718          * Initialise to 1 if this is a new superblock.
 719          */
 720         mddev->events = events_sb ? : 1;
 721
 722         /*
 723          * Reshaping is not currently allowed
 724          */
 725         if ((le32_to_cpu(sb->level) != mddev->level) ||
 726             (le32_to_cpu(sb->layout) != mddev->layout) ||
 727             (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) {
 728                 DMERR("Reshaping arrays not yet supported.");
 729                 return -EINVAL;
 730         }
 731
 732         /* We can only change the number of devices in RAID1 right now */
 733         if ((rs->raid_type->level != 1) &&
 734             (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
 735                 DMERR("Reshaping arrays not yet supported.");
 736                 return -EINVAL;
 737         }
 738
 739         if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)))
 740                 mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
 741
 742         /*
 743          * During load, we set FirstUse if a new superblock was written.
 744          * There are two reasons we might not have a superblock:
 745          * 1) The array is brand new - in which case, all of the
 746          *    devices must have their In_sync bit set.  Also,
 747          *    recovery_cp must be 0, unless forced.
 748          * 2) This is a new device being added to an old array
 749          *    and the new device needs to be rebuilt - in which
 750          *    case the In_sync bit will /not/ be set and
 751          *    recovery_cp must be MaxSector.
 752          */
 753         rdev_for_each(r, mddev) {
 754                 if (!test_bit(In_sync, &r->flags)) {
 755                         DMINFO("Device %d specified for rebuild: "
 756                                "Clearing superblock", r->raid_disk);
 757                         rebuilds++;
 758                 } else if (test_bit(FirstUse, &r->flags))
 759                         new_devs++;
 760         }
 761
 762         if (!rebuilds) {
 763                 if (new_devs == mddev->raid_disks) {
 764                         DMINFO("Superblocks created for new array");
 765                         set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
 766                 } else if (new_devs) {
 767                         DMERR("New device injected "
 768                               "into existing array without 'rebuild' "
 769                               "parameter specified");
 770                         return -EINVAL;
 771                 }
 772         } else if (new_devs) {
 773                 DMERR("'rebuild' devices cannot be "
 774                       "injected into an array with other first-time devices");
 775                 return -EINVAL;
 776         } else if (mddev->recovery_cp != MaxSector) {
 777                 DMERR("'rebuild' specified while array is not in-sync");
 778                 return -EINVAL;
 779         }
 780
 781         /*
 782          * Now we set the Faulty bit for those devices that are
 783          * recorded in the superblock as failed.
 784          */
 785         rdev_for_each(r, mddev) {
 786                 if (!r->sb_page)
 787                         continue;
 788                 sb2 = page_address(r->sb_page);
 789                 sb2->failed_devices = 0;
 790
 791                 /*
 792                  * Check for any device re-ordering.
 793                  */
 794                 if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
 795                         role = le32_to_cpu(sb2->array_position);
 796                         if (role != r->raid_disk) {
 797                                 if (rs->raid_type->level != 1) {
 798                                         rs->ti->error = "Cannot change device "
 799                                                 "positions in RAID array";
 800                                         return -EINVAL;
 801                                 }
 802                                 DMINFO("RAID1 device #%d now at position #%d",
 803                                        role, r->raid_disk);
 804                         }
 805
 806                         /*
 807                          * Partial recovery is performed on
 808                          * returning failed devices.
 809                          */
 810                         if (failed_devices & (1 << role))
 811                                 set_bit(Faulty, &r->flags);
 812                 }
 813         }
 814
 815         return 0;
 816 }
 817
 818 static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
 819 {
 820         struct dm_raid_superblock *sb = page_address(rdev->sb_page);
 821
 822         /*
 823          * If mddev->events is not set, we know we have not yet initialized
 824          * the array.
 825          */
 826         if (!mddev->events && super_init_validation(mddev, rdev))
 827                 return -EINVAL;
 828
 829         mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
 830         rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
 831         if (!test_bit(FirstUse, &rdev->flags)) {
 832                 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
 833                 if (rdev->recovery_offset != MaxSector)
 834                         clear_bit(In_sync, &rdev->flags);
 835         }
 836
 837         /*
 838          * If a device comes back, set it as not In_sync and no longer faulty.
 839          */
 840         if (test_bit(Faulty, &rdev->flags)) {
 841                 clear_bit(Faulty, &rdev->flags);
 842                 clear_bit(In_sync, &rdev->flags);
 843                 rdev->saved_raid_disk = rdev->raid_disk;
 844                 rdev->recovery_offset = 0;
 845         }
 846
 847         clear_bit(FirstUse, &rdev->flags);
 848
 849         return 0;
 850 }
 851
 852 /*
 853  * Analyse superblocks and select the freshest.
 854  */
 855 static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
 856 {
 857         int ret;
 858         unsigned redundancy = 0;
 859         struct raid_dev *dev;
 860         struct md_rdev *rdev, *tmp, *freshest;
 861         struct mddev *mddev = &rs->md;
 862
 863         switch (rs->raid_type->level) {
 864         case 1:
 865                 redundancy = rs->md.raid_disks - 1;
 866                 break;
 867         case 4:
 868         case 5:
 869         case 6:
 870                 redundancy = rs->raid_type->parity_devs;
 871                 break;
 872         default:
 873                 ti->error = "Unknown RAID type";
 874                 return -EINVAL;
 875         }
 876
 877         freshest = NULL;
 878         rdev_for_each_safe(rdev, tmp, mddev) {
 879                 if (!rdev->meta_bdev)
 880                         continue;
 881
 882                 ret = super_load(rdev, freshest);
 883
 884                 switch (ret) {
 885                 case 1:
 886                         freshest = rdev;
 887                         break;
 888                 case 0:
 889                         break;
 890                 default:
 891                         dev = container_of(rdev, struct raid_dev, rdev);
 892                         if (redundancy--) {
 893                                 if (dev->meta_dev)
 894                                         dm_put_device(ti, dev->meta_dev);
 895
 896                                 dev->meta_dev = NULL;
 897                                 rdev->meta_bdev = NULL;
 898
 899                                 if (rdev->sb_page)
 900                                         put_page(rdev->sb_page);
 901
 902                                 rdev->sb_page = NULL;
 903
 904                                 rdev->sb_loaded = 0;
 905
 906                                 /*
 907                                  * We might be able to salvage the data device
 908                                  * even though the meta device has failed.  For
 909                                  * now, we behave as though '- -' had been
 910                                  * set for this device in the table.
 911                                  */
 912                                 if (dev->data_dev)
 913                                         dm_put_device(ti, dev->data_dev);
 914
 915                                 dev->data_dev = NULL;
 916                                 rdev->bdev = NULL;
 917
 918                                 list_del(&rdev->same_set);
 919
 920                                 continue;
 921                         }
 922                         ti->error = "Failed to load superblock";
 923                         return ret;
 924                 }
 925         }
 926
 927         if (!freshest)
 928                 return 0;
 929
 930         /*
 931          * Validation of the freshest device provides the source of
 932          * validation for the remaining devices.
 933          */
 934         ti->error = "Unable to assemble array: Invalid superblocks";
 935         if (super_validate(mddev, freshest))
 936                 return -EINVAL;
 937
 938         rdev_for_each(rdev, mddev)
 939                 if ((rdev != freshest) && super_validate(mddev, rdev))
 940                         return -EINVAL;
 941
 942         return 0;
 943 }
 944
 945 /*
 946  * Construct a RAID4/5/6 mapping:
 947  * Args:
 948  *      <raid_type> <#raid_params> <raid_params>                \
 949  *      <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
 950  *
 951  * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
 952  * details on possible <raid_params>.
 953  */
 954 static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
 955 {
 956         int ret;
 957         struct raid_type *rt;
 958         unsigned long num_raid_params, num_raid_devs;
 959         struct raid_set *rs = NULL;
 960
 961         /* Must have at least <raid_type> <#raid_params> */
 962         if (argc < 2) {
 963                 ti->error = "Too few arguments";
 964                 return -EINVAL;
 965         }
 966
 967         /* raid type */
 968         rt = get_raid_type(argv[0]);
 969         if (!rt) {
 970                 ti->error = "Unrecognised raid_type";
 971                 return -EINVAL;
 972         }
 973         argc--;
 974         argv++;
 975
 976         /* number of RAID parameters */
 977         if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
 978                 ti->error = "Cannot understand number of RAID parameters";
 979                 return -EINVAL;
 980         }
 981         argc--;
 982         argv++;
 983
 984         /* Skip over RAID params for now and find out # of devices */
 985         if (num_raid_params + 1 > argc) {
 986                 ti->error = "Arguments do not agree with counts given";
 987                 return -EINVAL;
 988         }
 989
 990         if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
 991             (num_raid_devs >= INT_MAX)) {
 992                 ti->error = "Cannot understand number of raid devices";
 993                 return -EINVAL;
 994         }
 995
 996         rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
 997         if (IS_ERR(rs))
 998                 return PTR_ERR(rs);
 999
1000         ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
1001         if (ret)
1002                 goto bad;
1003
1004         ret = -EINVAL;
1005
1006         argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
1007         argv += num_raid_params + 1;
1008
1009         if (argc != (num_raid_devs * 2)) {
1010                 ti->error = "Supplied RAID devices does not match the count given";
1011                 goto bad;
1012         }
1013
1014         ret = dev_parms(rs, argv);
1015         if (ret)
1016                 goto bad;
1017
1018         rs->md.sync_super = super_sync;
1019         ret = analyse_superblocks(ti, rs);
1020         if (ret)
1021                 goto bad;
1022
1023         INIT_WORK(&rs->md.event_work, do_table_event);
1024         ti->private = rs;
1025         ti->num_flush_requests = 1;
1026
1027         mutex_lock(&rs->md.reconfig_mutex);
1028         ret = md_run(&rs->md);
1029         rs->md.in_sync = 0; /* Assume already marked dirty */
1030         mutex_unlock(&rs->md.reconfig_mutex);
1031
1032         if (ret) {
1033                 ti->error = "Fail to run raid array";
1034                 goto bad;
1035         }
1036
1037         rs->callbacks.congested_fn = raid_is_congested;
1038         dm_table_add_target_callbacks(ti->table, &rs->callbacks);
1039
1040         mddev_suspend(&rs->md);
1041         return 0;
1042
1043 bad:
1044         context_free(rs);
1045
1046         return ret;
1047 }
1048
1049 static void raid_dtr(struct dm_target *ti)
1050 {
1051         struct raid_set *rs = ti->private;
1052
1053         list_del_init(&rs->callbacks.list);
1054         md_stop(&rs->md);
1055         context_free(rs);
1056 }
1057
1058 static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_context)
1059 {
1060         struct raid_set *rs = ti->private;
1061         struct mddev *mddev = &rs->md;
1062
1063         mddev->pers->make_request(mddev, bio);
1064
1065         return DM_MAPIO_SUBMITTED;
1066 }
1067
1068 static int raid_status(struct dm_target *ti, status_type_t type,
1069                        char *result, unsigned maxlen)
1070 {
1071         struct raid_set *rs = ti->private;
1072         unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1073         unsigned sz = 0;
1074         int i, array_in_sync = 0;
1075         sector_t sync;
1076
1077         switch (type) {
1078         case STATUSTYPE_INFO:
1079                 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
1080
1081                 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1082                         sync = rs->md.curr_resync_completed;
1083                 else
1084                         sync = rs->md.recovery_cp;
1085
1086                 if (sync >= rs->md.resync_max_sectors) {
1087                         array_in_sync = 1;
1088                         sync = rs->md.resync_max_sectors;
1089                 } else {
1090                         /*
1091                          * The array may be doing an initial sync, or it may
1092                          * be rebuilding individual components.  If all the
1093                          * devices are In_sync, then it is the array that is
1094                          * being initialized.
1095                          */
1096                         for (i = 0; i < rs->md.raid_disks; i++)
1097                                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
1098                                         array_in_sync = 1;
1099                 }
1100                 /*
1101                  * Status characters:
1102                  *  'D' = Dead/Failed device
1103                  *  'a' = Alive but not in-sync
1104                  *  'A' = Alive and in-sync
1105                  */
1106                 for (i = 0; i < rs->md.raid_disks; i++) {
1107                         if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1108                                 DMEMIT("D");
1109                         else if (!array_in_sync ||
1110                                  !test_bit(In_sync, &rs->dev[i].rdev.flags))
1111                                 DMEMIT("a");
1112                         else
1113                                 DMEMIT("A");
1114                 }
1115
1116                 /*
1117                  * In-sync ratio:
1118                  *  The in-sync ratio shows the progress of:
1119                  *   - Initializing the array
1120                  *   - Rebuilding a subset of devices of the array
1121                  *  The user can distinguish between the two by referring
1122                  *  to the status characters.
1123                  */
1124                 DMEMIT(" %llu/%llu",
1125                        (unsigned long long) sync,
1126                        (unsigned long long) rs->md.resync_max_sectors);
1127
1128                 break;
1129         case STATUSTYPE_TABLE:
1130                 /* The string you would use to construct this array */
1131                 for (i = 0; i < rs->md.raid_disks; i++) {
1132                         if ((rs->print_flags & DMPF_REBUILD) &&
1133                             rs->dev[i].data_dev &&
1134                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
1135                                 raid_param_cnt += 2; /* for rebuilds */
1136                         if (rs->dev[i].data_dev &&
1137                             test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1138                                 raid_param_cnt += 2;
1139                 }
1140
1141                 raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2);
1142                 if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
1143                         raid_param_cnt--;
1144
1145                 DMEMIT("%s %u %u", rs->raid_type->name,
1146                        raid_param_cnt, rs->md.chunk_sectors);
1147
1148                 if ((rs->print_flags & DMPF_SYNC) &&
1149                     (rs->md.recovery_cp == MaxSector))
1150                         DMEMIT(" sync");
1151                 if (rs->print_flags & DMPF_NOSYNC)
1152                         DMEMIT(" nosync");
1153
1154                 for (i = 0; i < rs->md.raid_disks; i++)
1155                         if ((rs->print_flags & DMPF_REBUILD) &&
1156                             rs->dev[i].data_dev &&
1157                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
1158                                 DMEMIT(" rebuild %u", i);
1159
1160                 if (rs->print_flags & DMPF_DAEMON_SLEEP)
1161                         DMEMIT(" daemon_sleep %lu",
1162                                rs->md.bitmap_info.daemon_sleep);
1163
1164                 if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
1165                         DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1166
1167                 if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
1168                         DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1169
1170                 for (i = 0; i < rs->md.raid_disks; i++)
1171                         if (rs->dev[i].data_dev &&
1172                             test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1173                                 DMEMIT(" write_mostly %u", i);
1174
1175                 if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
1176                         DMEMIT(" max_write_behind %lu",
1177                                rs->md.bitmap_info.max_write_behind);
1178
1179                 if (rs->print_flags & DMPF_STRIPE_CACHE) {
1180                         struct r5conf *conf = rs->md.private;
1181
1182                         /* convert from kiB to sectors */
1183                         DMEMIT(" stripe_cache %d",
1184                                conf ? conf->max_nr_stripes * 2 : 0);
1185                 }
1186
1187                 if (rs->print_flags & DMPF_REGION_SIZE)
1188                         DMEMIT(" region_size %lu",
1189                                rs->md.bitmap_info.chunksize >> 9);
1190
1191                 DMEMIT(" %d", rs->md.raid_disks);
1192                 for (i = 0; i < rs->md.raid_disks; i++) {
1193                         if (rs->dev[i].meta_dev)
1194                                 DMEMIT(" %s", rs->dev[i].meta_dev->name);
1195                         else
1196                                 DMEMIT(" -");
1197
1198                         if (rs->dev[i].data_dev)
1199                                 DMEMIT(" %s", rs->dev[i].data_dev->name);
1200                         else
1201                                 DMEMIT(" -");
1202                 }
1203         }
1204
1205         return 0;
1206 }
1207
1208 static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
1209 {
1210         struct raid_set *rs = ti->private;
1211         unsigned i;
1212         int ret = 0;
1213
1214         for (i = 0; !ret && i < rs->md.raid_disks; i++)
1215                 if (rs->dev[i].data_dev)
1216                         ret = fn(ti,
1217                                  rs->dev[i].data_dev,
1218                                  0, /* No offset on data devs */
1219                                  rs->md.dev_sectors,
1220                                  data);
1221
1222         return ret;
1223 }
1224
1225 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1226 {
1227         struct raid_set *rs = ti->private;
1228         unsigned chunk_size = rs->md.chunk_sectors << 9;
1229         struct r5conf *conf = rs->md.private;
1230
1231         blk_limits_io_min(limits, chunk_size);
1232         blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1233 }
1234
1235 static void raid_presuspend(struct dm_target *ti)
1236 {
1237         struct raid_set *rs = ti->private;
1238
1239         md_stop_writes(&rs->md);
1240 }
1241
1242 static void raid_postsuspend(struct dm_target *ti)
1243 {
1244         struct raid_set *rs = ti->private;
1245
1246         mddev_suspend(&rs->md);
1247 }
1248
1249 static void raid_resume(struct dm_target *ti)
1250 {
1251         struct raid_set *rs = ti->private;
1252
1253         set_bit(MD_CHANGE_DEVS, &rs->md.flags);
1254         if (!rs->bitmap_loaded) {
1255                 bitmap_load(&rs->md);
1256                 rs->bitmap_loaded = 1;
1257         }
1258
1259         clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
1260         mddev_resume(&rs->md);
1261 }
1262
1263 static struct target_type raid_target = {
1264         .name = "raid",
1265         .version = {1, 2, 0},
1266         .module = THIS_MODULE,
1267         .ctr = raid_ctr,
1268         .dtr = raid_dtr,
1269         .map = raid_map,
1270         .status = raid_status,
1271         .iterate_devices = raid_iterate_devices,
1272         .io_hints = raid_io_hints,
1273         .presuspend = raid_presuspend,
1274         .postsuspend = raid_postsuspend,
1275         .resume = raid_resume,
1276 };
1277
1278 static int __init dm_raid_init(void)
1279 {
1280         return dm_register_target(&raid_target);
1281 }
1282
1283 static void __exit dm_raid_exit(void)
1284 {
1285         dm_unregister_target(&raid_target);
1286 }
1287
1288 module_init(dm_raid_init);
1289 module_exit(dm_raid_exit);
1290
1291 MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
1292 MODULE_ALIAS("dm-raid4");
1293 MODULE_ALIAS("dm-raid5");
1294 MODULE_ALIAS("dm-raid6");
1295 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1296 MODULE_LICENSE("GPL");